Jobs!
http://www.finchpark.com/books/tmms/
Hey, I also have to teach a conversation club once a week and decided to buy a book that I used before with students back home. It has convo topics to guide them ie. What would you take on a desert island- then they fill in/circle what they would take and then everyone discusses it.It is called the Non-Stop Discussion Workbook by George Rooks and you can get it on a high beginner, low int. level. Obviously, if your school will not pay for a few, buy one for yourself and just photocopy from it each week.
I'm using 'Discussion: Process and Principles' Compass Publishing, and it's pretty good so far. It has good topics and discussion principles to teach. These extra classes are seriously challenging for me, so if you feel the same way, know you are not alone!